The frame of an aircraft includes longitudinally-extending stringers to which body panels are riveted at locations which match the inside mold line (IML) of the body of the aircraft. To ensure that the contour of a stringer matches, within tolerances, the IML of an aircraft body, aircraft manufacturers typically require that the stringers be checked for compliance with the designed IML at several locations or stations along the length of the stringer. Prior methods for checking if a stringer is within specifications have not been entirely satisfactory, being highly expensive and/or time-consuming.